Causal analyses of effects of drug use on health will continue with special attention to: a. Write up and submit for publication analyses already conducted of patterns of drug involvement; increased health hazards of inhalants use. b. Further specification of findings regarding effects of heroin. c. Differential effects of drug use for males and females. (Note that female heroin and inhalant users were heavier users of those substances than were males who used them.) d. Time lag or "incubation" period, as well as role of other variables of drug use (early onset, heaviness of use, recency of use) in producing health effects. It appears from analysis of glue-inhalant effects to date that they are "delayed"--reported at reinterview, not in initial interview, even when use had already occurred. Heroin's effects, to the contrary, seem to appear more immediately, with those who using by initial interview already showing poorer physical health at t1 interview; male heroin initiators (between the two interviews) showed greater change in health. e. Controlling data in other domains (psychosocial, etc.) to qualify and specify drug effects on health. Put briefly, the question at issue: Is it the drug used or other characteristics of the drug user which produces effects? f. With hypotheses developed from these analyses in place, we intend to test the relationship between specified drug use, effects from other domains and health change via the Lisrel model for maximum likelihood analysis of linear structural relationships.